Signal function

The fuel injector control module (FICM) requires a 12-volt power source. The FICM receives power from the vehicle batteries through the FICM relay contacts each time the ignition is turned on. The powertrain control module (PCM) communicates with the FICM utilizing controller area network (CAN) protocol. The CAN protocol is an international standards organization (ISO) standard for serial data communication. The CAN standard includes a physical layer using differential transmission on a twisted pair of wires and a data link layer that defines a few different message types, arbitration rules for bus access and methods for fault detection and fault confinement.